Segmental grinding wheel



Dec. 27, 1932. T. LARSSON SEGMENTAL GRINDING WHEEL Filed June 12, 1926Witneses Uhure fiarsson Patented Dec. 27, 1932 UNITED STATES THURELARSSON, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO NORTON COMPANY, OFWORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS SEGMENTALGRINDING WHEEL Application filed June 12,

This invention relates to grinding wheels and more particularly to achuck for holding abrasive segments for use on a surface grindinmachine.

It has been common to make surface grinding wheels in the form of asolidring of abrasive material and fasten this ring to a metallic chuck bymeans of sulphur or other suitable cementing material. Such rings areexpensive to make and are frequently broken during the process ofmanufacture as well as during use.

In a chuck for a segmental surface grinding wheel, it is essential thatthe abrasive sega ments be held rigidly in the chuck at a point as nearas possible to the operative grinding surfaces to prevent Vibration andbreakage of the segments. In such constructions it is necessary,therefore to adjust the position of the segments frequently as theybecome worn. In former constructions, the segments have not beenproperly supported in the chuck and it has been difficult to adjusttheirposltion relative to thechuck. a

It is an object of the invention to overcome these difficulties and toprovide a practical fastening device to hold abrasive segments in placeon a driving head of a machine in various positions ofadjustment acplaceupon the segments.

- It is another object of the invention to provide a chuck for holdingabrasive segments rigidly so that the grinding surfaces will bemaintained aligned during grinding and may be easily and readilyrepositioned when worn.

It is a further object of the invention to provide abrasive segments soconstructed that they might be arranged and mounted upon a supportingmember in such a manner as to be readily and conveniently repositionedwhen Worn relative to the supporting member. I

In accordance with theinvention-a grinding wheel is provided composed ofa plurality of abrasive segments specially shaped for mounting on asuitable supporting member, such as a ring. -The segments are adjustablyheld on. the supporting member so that they may be moved when worn toextend beyond which,

cording to the degree of wear which has taken 1926. Serial No. 115,629:

an edge of the supporting member to present a fiat grinding surface. Anadjustable stop is provided which is arranged to engage the end of eachsegment opposite the grinding surface to locate their positions and holdthem rigidly in alignment during grinding. The segments'may be heldagainst the supporting member conveniently by alternately fixed andadjustable clamping devices, preferably, of wedge shape and positionedbe tween the segments.

The invention will be more clearly understood from the followingdescription in conjunction with the accompanying drawing; in

. v Fig. 1 is an end elevation of a segmental abrasive wheel;

Fig. 2 is a. sectional view taken on the lin 22 of Fig.1; I x r Fig. 3is a sectional View taken on the line 33 of Fig. 2 showing the abrasivesegments in one position relative to the, supporting member;

Fig. 4 is a similar sectional view showing the abrasive segmentsadvanced to another position relative to the supporting member; Fig. 5is a similar sectional view showing the abrasive blocks advanced toathird holding position; 3

Fig. 6 is a plan View of a suitable form of adjustable stop which isadapted to engage the ends of each abrasive segment opposite thegrinding surface; and I .Fig. 7 is a perspective view of the fixedclamping device embodying means for hold "ing the adjustablestop.-

In the drawing, I have illustrated a segmental surface grinding wheelembodying and illustrating the invention. This wheel comprises asupporting member 10, such as a ring, adapted to be secured to anysuitable rotatable driving head 11 shown in dotted lines in Figs. 3, 4or 5 which is secured to or integral with any of the well known grindingwheel spindle constructions in any suitable manner, such for example asby screws 12. A plurality of abrasive segments 14 are suitably shaped toengage a surface of the supporting member, and for this urpose lands 15,preferably, are provided. he end 100 of each abrasive segment isprovided with a flat grinding surface 20, and when the segments are inoperative position they extent asubstantial distance beyond one edge ofthe member 10.

The segments 14 are adjustably held against a surface of the supportingmember 10 in any suitable manner, but as illustrated a clamping device16, preferably of wedge shape, is provided integral with or secured tothe supporting member 10 by means of screws 17 and is adapted to engageone side of each adjacent segment. The other side of each segment isengaged by an adjustable clamping device 18, preferably of wedge shape,which is connected to the supporting member 10 by means of an adjustingscrew 19. The abrasive segments 14 are provided with side faces adaptedto engage the clamping devices, and in accordance with the referredconstruction have side clamping ace portions which converge in anoutward direction. The spaced projecting lands and the bevelled clampingsurfaces engaged by the clamping blocks 18 are located opposite eachother so that the clamping pressure will be transmittedradially inwardlyand directly from the clamping blocks to the convex cylindricalsupporting surface of the ring 10. It will also be observed that theclamping blocks lie wholly between the ends of the segments and sopermit the wheel to grind up to a shoulder.

In order to secure rigidity of the wheel during grinding the end surfaceof each abraring 24 is adapted to engage the end surface is engaged andsupported by an adjustable stop operatively associated with thesupporting member 10. A suitable arrangement for this purpose mayinclude a ring 24., or other suitable device, provided with a pluralityof tongues 25 adapted to engage the aligned holding surfaces 26, or thesurfaces 27 or 28, each of which locates parallel Planes (see Figs. 3,4, 5 and 7 These surfaces are preferably integral with or otherwiserigidly secured to the supporting member 10, and are arranged to face inthe same direction as the grinding surface 20. An extension 30 on thering 24 is adapted to engage the end surface of each abrasive segmentopposite the flat grinding surface.

The tongues 25 on the adjustable stop, or ring 24, are spaced so as toleave openings 31 therebetween such that the ring 24* may be moved aboutthe supporting member 10 to engage the holding surfaces 26 or may bedisengaged therefrom and moved in the direction of an elementof thesupporting member 10 to another parallel plane, such as that located bythe aligned surfaces 27 or 28, the openings 31 permitting the axialmovement of the ring pastthe projections 29. The

projections 29 may be formed'integral with the supporting member 10, oras shown in the drawing may be separably mountable thereupon so as torest against a shoulder 32 on the member 10 and he held securelythereupon by screws 33; As: shown in the drawing the projections 29 arerepresented as an integral part of the clamping device 16 but it isobvious that this is not necessary and that both the clamping devices 16and the projections 29 may be formed as separate and entirelyindependent parts.

7 When the abrasive segments 14 are properly assembled for grinding uponthe supporting member 10 they extend a substantial distance beyond oneedge of the supporting member 10, as clearly indicated in any one ofFigs. 3,4 or 5. Fig. 3 shows the se ments assembled in the chuck intheir initial position and held against the supporting member 10 by theclamping devices 16 and 18. During use the the abrasive segmentsgraduall wear until the fiat grinding surface is rought close to theedge of the supporting member 10. It is then necessary to reposition theabrasive segments so that they extend a substantial distance beyond thesupporting member 10 to present an operative fiat grinding surface.

This may be done by loosening the screws I 19 to release the clampingdevices 18 which permits the abrasive segments 14 to .be moved in thedirection of an element of the supporting member 10 to position themappropriately beyond the edge of the member 10. The ring 24 is thenturned to disengage the tongues and the holding surfaces 26 and bringthe openings 31 over the projections 29. The ring 24 is then moved alongan element of the member 10 until the tongues 25 are brought into theplane located by the aligned holding surfaces 27 and is then turneduntil the tongues 25 are brought into engagement with the surfaces 27.The abrasive segments 14 are then moved to bring that end surface ofeach which is opposite the fiat grinding surface into engagement withthe extension of the ring 24. The screws 19 are tightened so as toadjust the clamping devices 18 against the abrasive segments and holdthe latter against the supporting member 10 in the position indicated inFig. 4. Likewise, when the abrasive segments become worn again they may.be moved from the position indicated in Fig.4 to'that indicated in Fig.5. By the provisions of'the invention a segmental surface grinding wheelmay be constructed in which the abrasive segments are held in a rigidand satisfactory relation, and yet which may be conveniently and readilyadjusted to accurately reposition the segments as desired when worn andhold them in an equally rigid manner.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is;

1. A grinding wheel comprising a chuck having a substantially circularsupporting surface, a pluralit of abrasive segments mounted as an annuus against said surface in an adjusted position and extending beyond oneedge thereof to present a substantially continuous fiat grindingsurface, clamping devices on the chuck in engagement with the segmentswhich are separately adjustable to press the segments against saidsupporting surface, a single stop mounted on and adjustable relative tothe chuck, and means cooperating therewith which serves to locate the"stop in one of several predetermined positions, andthereby align thegrinding faces of the segments in each adjusted position.

2. A grinding wheelcomprising a chuck,

having an outer cylindrical supporting sur face, a plurality of abrasivesegments mountgle stop mounted on the chuck which engages the ends ofall of the segments to adjustably position their operative faces inalignment, and means to secure the stop in one of several predeterminedpositions to locate the segments as desired.

3. A grinding wheel comprising a chuck having a supporting ring, aplurality of abrasive segments mounted against a curved surface of saidring, individually adjustable clamping blocks, each engaging twoadjacent segments to secure them on the ring, and a single stopinterlockingly secured on said ring which is adjustable to one ofseveral predetermined and spaced positions and which engages the ends ofall of the segments when secured in each of these adjusted positions andmaintains their grinding faces aligned to form a flat grinding surface.

4. A segmental surface grinding wheel comprising a supporting ring, aplurality of abrasive segments shaped for mounting upon the surface ofsaid ring, adjustable clamping blocks engaging adjacent segments tosecure them on the ring, a stop ring rotatably mounted on the supportingring and having several locking lugs, and means on the supporting ringto interlock therewith when the stop ring is rotated through a partialturn.

5. A segmentalsurface grindingwheel comprising a supporting ring, aplurality of abrasive segments shaped-for mounting upon the surface ofsaid ring, adjustable clamping blocks engaging adjacent segments tosecure them on the ring, a stop ring surrounding said supporting ringand having locking lugs, and means on the supporting member to interlocktherewith when the parts are rotated relatively.

6. A segmental surface grinding wheel comprising a supporting ring, aplurality of abrasive segments shaped for mounting upon the surface ofsaid ring, adjustable clamping blocks engaging adjacent segments tosecure them on the ring, a stopring surrounding the supporting ring''and having locking lugs, and means including spaced projections on thesupporting ring arranged to interlock with,

the lugs on the stop ring to secure the latter in one of severalpositions and locate the segments as desired.

7. A segmental surface grinding wheel comprising a supporting member, aplurality of abrasive segments mounted on the supporting member in. anadjusted position and extending beyond one edge thereof to present aflat grinding surface, clamping devices engaging the segment which areseparately adjustable to press the segments against the surface of thesupporting member, and a stop engaging the ends of several segments,said stop and supporting member having aplurality of interlocking partswhich permit the stop to belocatedin any one of several positions orunlocked directly therefrom.

8. A'segmental grinding wheel comprising I a rotatable ring, a pluralityof abrasive seg ments mounted thereagainst and projecting to form anexposed, substantially plane grinding face, clamping blocks adjustablysecured .to the ring and engaging the segments to hold them. inposition, a ring shaped stop engaging the ends of the segments to aligntheir grinding faces and having spaced looking lugs thereon, and aplurality of rows of spaced members carried on the rotatable ring whichmay interlock with the lugs and hold the ring and the segments in one ofseveral adgusted positions. t

A segmental surface grinding wheel comprising a supporting ring,abrasive segments for mounting thereupon, means to adjustably hold saidsegments against a peripheral surface of said ring includingspaced wedgeblocks rigidly secured to said ring to support and correctly positionopposed edges of adjacent segments, adjustable clamping blocks mountedon said ring and engaging the opposite sides of said segments toposition the same so as to provide a flat grinding surface extending.beyond one edge of said ring, and an ad ustable stop engaging the endfaces of the segments adapted to prevent endwise movement/thereof.

. 10. A segmental grinding wheel comprising a supporting ring, abrasivesegments mounted thereon, means to adjustably hold said segments againsta peripheral surface of said ring including spaced wedge blocks rigidlysecured to said ring to support and correctly position opposed sides ofadjacent segments, adjustable clamping blocks mounted on said ring andengaging the opposite sides of said segments to posltion the same so asto provide a flat grinding surface extending beyond the edge of saidring, a stop engaging the end faces of the segments adapted to preventendwise movement thereof, and means for locating the stop in one ofseveral adjusted positions to reposition the abrasive segments as theywear away.

11. A segmental surface grinding wheel comprising a supporting member, aplurality of projections integrally fixed thereto providing alignedsurfaces adapted to locate a plurality of parallel planes, abrasivesegments adjustably mounted upon the member, a movable stop surroundingsaid member and provided with a tongue adapted to engage those surfaceslocating agiven plane, said stop being constructed and arranged toengage one end of each segment and maintain the opposite endsalignedduring grinding to form a fiat grinding surface beyond one edgeof said member and facing in the same direction as said surfaces.

12. A segmental surface grinding wheel comprising a supporting member, aplurality of projections integrally fixed thereto providing alignedsurfaces adapted to locate a plurality of parallel planes, abrasivesegments adjustably mounted upon the member, a movable stop surroundingsaid member and provided with a plurality of tongues spacedso that saidmembers may be moved to bring said tongues in engagement with any ofthose surfaces locating any one of a plurality of parallel planes, saidstop being constructed and arranged to engage one end of each segmentand maintain the opposite ends aligned during grinding to present a flatgrinding surface beyond one edge of said member and facing in the samedirection as said surfaces.

13. A segmental surface grinding wheel comprising a supporting member, aplurality of abrasive segments mounted upon said member betweenalternate fixed and adjustable clamping blocks so that the segments maybe moved along an element of said member as desired, a plurality ofprojections integrally fixed upon the member providing aligned surfacesadapted to locate a plurality of different parallel planes, a movablestop surrounding said member and provided with a tongue adapted toengage the surfaces locating a given plane, said stop being constructedand arranged to engage one end of each segment and maintain the oppositeends aligned during grinding to present a flat grinding surface beyondone edge of said member.

14. An abrasive segment for use in a chuck having a convex cylindricalsupporting surface comprislng a shaped mass of bonded abrasive grainshaving a plane grinding face, an inner surface provided with a pair ofspaced projecting lands adjacent the ends of \the segment which areshaped to fit against and form the sole contact with the convex surface,and .an outer face havmg bevelled I clamping surfaces adjacent to itsends which converge outwardly and are shaped to be en-

